"Brazil obtained 37% of all African slaves traded, and close to 4 million slaves were sent to this one country. Starting around 1550, the Portuguese began to trade African slaves to work the sugar plantations once the native Tupi people deteriorated."

"The blacks brought to Brazil were from different ethnicities and from different African regions. Gilberto Freyre noted the major differences between these groups. Some Sudanese peoples, such as Hausa, Fula and others were Islamic, spoke Arabic and many of them could readand write in this language. Freyre noted that many slaves were better educated than their masters, because many Muslim slaves wereliterate in Arabic, while many Portuguese Brazilian masters could not even read or write in Portuguese." Read more here / source